/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/

/*
 *  X.509 certificate parsing and verification
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */
/*
 *  The ITU-T X.509 standard defines a certificate format for PKI.
 *
 *  http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
 *  http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
 *  http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
 *
 *  http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
 *  http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
 */

#include "tls/config.h"

#if defined(MBEDTLS_X509_CRT_PARSE_C)

#include "tls/x509_crt.h"
#include "tls/oid.h"

#include <stdio.h>
#include <string.h>

#if defined(MBEDTLS_PEM_PARSE_C)
#include "tls/pem.h"
#endif

#if defined(MBEDTLS_PLATFORM_C)
#include "tls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_free       free
#define mbedtls_calloc    calloc
#define mbedtls_snprintf   snprintf
#endif

#if defined(MBEDTLS_THREADING_C)
#include "tls/threading.h"
#endif

#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
#include <windows.h>
#include <intsafe.h>
#else
#include <time.h>
#endif

#if defined(MBEDTLS_FS_IO)
#include <stdio.h>
#if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#endif							/* !_WIN32 || EFIX64 || EFI32 */
#endif

/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize(void *v, size_t n)
{
	volatile unsigned char *p = v;
	while (n--) {
		*p++ = 0;
	}
}

/*
 * Default profile
 */
const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default = {
	/* Hashes from SHA-1 and above */
	MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA1) | MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_RIPEMD160) | MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA224) | MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA256) | MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA384) | MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA512),
	0xFFFFFFF,					/* Any PK alg    */
	0xFFFFFFF,					/* Any curve     */
	2048,
};

/*
 * Next-default profile
 */
const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next = {
	/* Hashes from SHA-256 and above */
	MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA256) | MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA384) | MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA512),
	0xFFFFFFF,					/* Any PK alg    */
#if defined(MBEDTLS_ECP_C)
	/* Curves at or above 128-bit security level */
	MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP256R1) | MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP384R1) | MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP521R1) | MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP256R1) | MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP384R1) | MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP512R1) | MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP256K1),
#else
	0,
#endif
	2048,
};

/*
 * NSA Suite B Profile
 */
const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb = {
	/* Only SHA-256 and 384 */
	MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA256) | MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA384),
	/* Only ECDSA */
	MBEDTLS_X509_ID_FLAG(MBEDTLS_PK_ECDSA),
#if defined(MBEDTLS_ECP_C)
	/* Only NIST P-256 and P-384 */
	MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP256R1) | MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP384R1),
#else
	0,
#endif
	0,
};

/*
 * Check md_alg against profile
 * Return 0 if md_alg acceptable for this profile, -1 otherwise
 */
static int x509_profile_check_md_alg(const mbedtls_x509_crt_profile *profile, mbedtls_md_type_t md_alg)
{
	if ((profile->allowed_mds & MBEDTLS_X509_ID_FLAG(md_alg)) != 0) {
		return (0);
	}

	return (-1);
}

/*
 * Check pk_alg against profile
 * Return 0 if pk_alg acceptable for this profile, -1 otherwise
 */
static int x509_profile_check_pk_alg(const mbedtls_x509_crt_profile *profile, mbedtls_pk_type_t pk_alg)
{
	if ((profile->allowed_pks & MBEDTLS_X509_ID_FLAG(pk_alg)) != 0) {
		return (0);
	}

	return (-1);
}

/*
 * Check key against profile
 * Return 0 if pk_alg acceptable for this profile, -1 otherwise
 */
static int x509_profile_check_key(const mbedtls_x509_crt_profile *profile, mbedtls_pk_type_t pk_alg, const mbedtls_pk_context *pk)
{
#if defined(MBEDTLS_RSA_C)
	if (pk_alg == MBEDTLS_PK_RSA || pk_alg == MBEDTLS_PK_RSASSA_PSS) {
		if (mbedtls_pk_get_bitlen(pk) >= profile->rsa_min_bitlen) {
			return (0);
		}

		return (-1);
	}
#endif

#if defined(MBEDTLS_ECP_C)
	if (pk_alg == MBEDTLS_PK_ECDSA || pk_alg == MBEDTLS_PK_ECKEY || pk_alg == MBEDTLS_PK_ECKEY_DH) {
		mbedtls_ecp_group_id gid = mbedtls_pk_ec(*pk)->grp.id;

		if ((profile->allowed_curves & MBEDTLS_X509_ID_FLAG(gid)) != 0) {
			return (0);
		}

		return (-1);
	}
#endif

	return (-1);
}

/*
 *  Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
 */
static int x509_get_version(unsigned char **p, const unsigned char *end, int *ver)
{
	int ret;
	size_t len;

	if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0)) != 0) {
		if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
			*ver = 0;
			return (0);
		}

		return (ret);
	}

	end = *p + len;

	if ((ret = mbedtls_asn1_get_int(p, end, ver)) != 0) {
		return (MBEDTLS_ERR_X509_INVALID_VERSION + ret);
	}

	if (*p != end) {
		return (MBEDTLS_ERR_X509_INVALID_VERSION + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	return (0);
}

/*
 *  Validity ::= SEQUENCE {
 *       notBefore      Time,
 *       notAfter       Time }
 */
static int x509_get_dates(unsigned char **p, const unsigned char *end, mbedtls_x509_time *from, mbedtls_x509_time *to)
{
	int ret;
	size_t len;

	if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
		return (MBEDTLS_ERR_X509_INVALID_DATE + ret);
	}

	end = *p + len;

	if ((ret = mbedtls_x509_get_time(p, end, from)) != 0) {
		return (ret);
	}

	if ((ret = mbedtls_x509_get_time(p, end, to)) != 0) {
		return (ret);
	}

	if (*p != end) {
		return (MBEDTLS_ERR_X509_INVALID_DATE + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	return (0);
}

/*
 * X.509 v2/v3 unique identifier (not parsed)
 */
static int x509_get_uid(unsigned char **p, const unsigned char *end, mbedtls_x509_buf *uid, int n)
{
	int ret;

	if (*p == end) {
		return (0);
	}

	uid->tag = **p;

	if ((ret = mbedtls_asn1_get_tag(p, end, &uid->len, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | n)) != 0) {
		if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
			return (0);
		}

		return (ret);
	}

	uid->p = *p;
	*p += uid->len;

	return (0);
}

static int x509_get_basic_constraints(unsigned char **p, const unsigned char *end, int *ca_istrue, int *max_pathlen)
{
	int ret;
	size_t len;

	/*
	 * BasicConstraints ::= SEQUENCE {
	 *      cA                      BOOLEAN DEFAULT FALSE,
	 *      pathLenConstraint       INTEGER (0..MAX) OPTIONAL }
	 */
	*ca_istrue = 0;				/* DEFAULT FALSE */
	*max_pathlen = 0;			/* endless */

	if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
	}

	if (*p == end) {
		return (0);
	}

	if ((ret = mbedtls_asn1_get_bool(p, end, ca_istrue)) != 0) {
		if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
			ret = mbedtls_asn1_get_int(p, end, ca_istrue);
		}

		if (ret != 0) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
		}

		if (*ca_istrue != 0) {
			*ca_istrue = 1;
		}
	}

	if (*p == end) {
		return (0);
	}

	if ((ret = mbedtls_asn1_get_int(p, end, max_pathlen)) != 0) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
	}

	if (*p != end) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	(*max_pathlen)++;

	return (0);
}

static int x509_get_ns_cert_type(unsigned char **p, const unsigned char *end, unsigned char *ns_cert_type)
{
	int ret;
	mbedtls_x509_bitstring bs = { 0, 0, NULL };

	if ((ret = mbedtls_asn1_get_bitstring(p, end, &bs)) != 0) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
	}

	if (bs.len != 1) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_INVALID_LENGTH);
	}

	/* Get actual bitstring */
	*ns_cert_type = *bs.p;
	return (0);
}

static int x509_get_key_usage(unsigned char **p, const unsigned char *end, unsigned int *key_usage)
{
	int ret;
	size_t i;
	mbedtls_x509_bitstring bs = { 0, 0, NULL };

	if ((ret = mbedtls_asn1_get_bitstring(p, end, &bs)) != 0) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
	}

	if (bs.len < 1) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_INVALID_LENGTH);
	}

	/* Get actual bitstring */
	*key_usage = 0;
	for (i = 0; i < bs.len && i < sizeof(unsigned int); i++) {
		*key_usage |= (unsigned int)bs.p[i] << (8 * i);
	}

	return (0);
}

/*
 * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
 *
 * KeyPurposeId ::= OBJECT IDENTIFIER
 */
static int x509_get_ext_key_usage(unsigned char **p, const unsigned char *end, mbedtls_x509_sequence *ext_key_usage)
{
	int ret;

	if ((ret = mbedtls_asn1_get_sequence_of(p, end, ext_key_usage, MBEDTLS_ASN1_OID)) != 0) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
	}

	/* Sequence length must be >= 1 */
	if (ext_key_usage->buf.p == NULL) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_INVALID_LENGTH);
	}

	return (0);
}

/*
 * SubjectAltName ::= GeneralNames
 *
 * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
 *
 * GeneralName ::= CHOICE {
 *      otherName                       [0]     OtherName,
 *      rfc822Name                      [1]     IA5String,
 *      dNSName                         [2]     IA5String,
 *      x400Address                     [3]     ORAddress,
 *      directoryName                   [4]     Name,
 *      ediPartyName                    [5]     EDIPartyName,
 *      uniformResourceIdentifier       [6]     IA5String,
 *      iPAddress                       [7]     OCTET STRING,
 *      registeredID                    [8]     OBJECT IDENTIFIER }
 *
 * OtherName ::= SEQUENCE {
 *      type-id    OBJECT IDENTIFIER,
 *      value      [0] EXPLICIT ANY DEFINED BY type-id }
 *
 * EDIPartyName ::= SEQUENCE {
 *      nameAssigner            [0]     DirectoryString OPTIONAL,
 *      partyName               [1]     DirectoryString }
 *
 * NOTE: we only parse and use dNSName at this point.
 */
static int x509_get_subject_alt_name(unsigned char **p, const unsigned char *end, mbedtls_x509_sequence *subject_alt_name)
{
	int ret;
	size_t len, tag_len;
	mbedtls_asn1_buf *buf;
	unsigned char tag;
	mbedtls_asn1_sequence *cur = subject_alt_name;

	/* Get main sequence tag */
	if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
	}

	if (*p + len != end) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	while (*p < end) {
		if ((end - *p) < 1) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_OUT_OF_DATA);
		}

		tag = **p;
		(*p)++;
		if ((ret = mbedtls_asn1_get_len(p, end, &tag_len)) != 0) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
		}

		if ((tag & MBEDTLS_ASN1_CONTEXT_SPECIFIC) != MBEDTLS_ASN1_CONTEXT_SPECIFIC) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
		}

		/* Skip everything but DNS name */
		if (tag != (MBEDTLS_ASN1_CONTEXT_SPECIFIC | 2)) {
			*p += tag_len;
			continue;
		}

		/* Allocate and assign next pointer */
		if (cur->buf.p != NULL) {
			if (cur->next != NULL) {
				return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS);
			}

			cur->next = mbedtls_calloc(1, sizeof(mbedtls_asn1_sequence));

			if (cur->next == NULL) {
				return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_ALLOC_FAILED);
			}

			cur = cur->next;
		}

		buf = &(cur->buf);
		buf->tag = tag;
		buf->p = *p;
		buf->len = tag_len;
		*p += buf->len;
	}

	/* Set final sequence entry's next pointer to NULL */
	cur->next = NULL;

	if (*p != end) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	return (0);
}

/*
 * X.509 v3 extensions
 *
 */
static int x509_get_crt_ext(unsigned char **p, const unsigned char *end, mbedtls_x509_crt *crt)
{
	int ret;
	size_t len;
	unsigned char *end_ext_data, *end_ext_octet;

	if ((ret = mbedtls_x509_get_ext(p, end, &crt->v3_ext, 3)) != 0) {
		if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
			return (0);
		}

		return (ret);
	}

	while (*p < end) {
		/*
		 * Extension  ::=  SEQUENCE  {
		 *      extnID      OBJECT IDENTIFIER,
		 *      critical    BOOLEAN DEFAULT FALSE,
		 *      extnValue   OCTET STRING  }
		 */
		mbedtls_x509_buf extn_oid = { 0, 0, NULL };
		int is_critical = 0;	/* DEFAULT FALSE */
		int ext_type = 0;

		if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
		}

		end_ext_data = *p + len;

		/* Get extension ID */
		extn_oid.tag = **p;

		if ((ret = mbedtls_asn1_get_tag(p, end, &extn_oid.len, MBEDTLS_ASN1_OID)) != 0) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
		}

		extn_oid.p = *p;
		*p += extn_oid.len;

		if ((end - *p) < 1) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_OUT_OF_DATA);
		}

		/* Get optional critical */
		if ((ret = mbedtls_asn1_get_bool(p, end_ext_data, &is_critical)) != 0 && (ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
		}

		/* Data should be octet string type */
		if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &len, MBEDTLS_ASN1_OCTET_STRING)) != 0) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret);
		}

		end_ext_octet = *p + len;

		if (end_ext_octet != end_ext_data) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
		}

		/*
		 * Detect supported extensions
		 */
		ret = mbedtls_oid_get_x509_ext_type(&extn_oid, &ext_type);

		if (ret != 0) {
			/* No parser found, skip extension */
			*p = end_ext_octet;

#if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
			if (is_critical) {
				/* Data is marked as critical: fail */
				return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
			}
#endif
			continue;
		}

		/* Forbid repeated extensions */
		if ((crt->ext_types & ext_type) != 0) {
			return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS);
		}

		crt->ext_types |= ext_type;

		switch (ext_type) {
		case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS:
			/* Parse basic constraints */
			if ((ret = x509_get_basic_constraints(p, end_ext_octet, &crt->ca_istrue, &crt->max_pathlen)) != 0) {
				return (ret);
			}
			break;

		case MBEDTLS_X509_EXT_KEY_USAGE:
			/* Parse key usage */
			if ((ret = x509_get_key_usage(p, end_ext_octet, &crt->key_usage)) != 0) {
				return (ret);
			}
			break;

		case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE:
			/* Parse extended key usage */
			if ((ret = x509_get_ext_key_usage(p, end_ext_octet, &crt->ext_key_usage)) != 0) {
				return (ret);
			}
			break;

		case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
			/* Parse subject alt name */
			if ((ret = x509_get_subject_alt_name(p, end_ext_octet, &crt->subject_alt_names)) != 0) {
				return (ret);
			}
			break;

		case MBEDTLS_X509_EXT_NS_CERT_TYPE:
			/* Parse netscape certificate type */
			if ((ret = x509_get_ns_cert_type(p, end_ext_octet, &crt->ns_cert_type)) != 0) {
				return (ret);
			}
			break;

		default:
			return (MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE);
		}
	}

	if (*p != end) {
		return (MBEDTLS_ERR_X509_INVALID_EXTENSIONS + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	return (0);
}

/*
 * Parse and fill a single X.509 certificate in DER format
 */
static int x509_crt_parse_der_core(mbedtls_x509_crt *crt, const unsigned char *buf, size_t buflen)
{
	int ret;
	size_t len;
	unsigned char *p, *end, *crt_end;
	mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;

	memset(&sig_params1, 0, sizeof(mbedtls_x509_buf));
	memset(&sig_params2, 0, sizeof(mbedtls_x509_buf));
	memset(&sig_oid2, 0, sizeof(mbedtls_x509_buf));

	/*
	 * Check for valid input
	 */
	if (crt == NULL || buf == NULL) {
		return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
	}
	// Use the original buffer until we figure out actual length
	p = (unsigned char *)buf;
	len = buflen;
	end = p + len;

	/*
	 * Certificate  ::=  SEQUENCE  {
	 *      tbsCertificate       TBSCertificate,
	 *      signatureAlgorithm   AlgorithmIdentifier,
	 *      signatureValue       BIT STRING  }
	 */
	if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (MBEDTLS_ERR_X509_INVALID_FORMAT);
	}

	if (len > (size_t)(end - p)) {
		mbedtls_x509_crt_free(crt);
		return (MBEDTLS_ERR_X509_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}
	crt_end = p + len;

	// Create and populate a new buffer for the raw field
	crt->raw.len = crt_end - buf;
	crt->raw.p = p = mbedtls_calloc(1, crt->raw.len);
	if (p == NULL) {
		return (MBEDTLS_ERR_X509_ALLOC_FAILED);
	}

	memcpy(p, buf, crt->raw.len);

	// Direct pointers to the new buffer
	p += crt->raw.len - len;
	end = crt_end = p + len;

	/*
	 * TBSCertificate  ::=  SEQUENCE  {
	 */
	crt->tbs.p = p;

	if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (MBEDTLS_ERR_X509_INVALID_FORMAT + ret);
	}

	end = p + len;
	crt->tbs.len = end - crt->tbs.p;

	/*
	 * Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
	 *
	 * CertificateSerialNumber  ::=  INTEGER
	 *
	 * signature            AlgorithmIdentifier
	 */
	if ((ret = x509_get_version(&p, end, &crt->version)) != 0 || (ret = mbedtls_x509_get_serial(&p, end, &crt->serial)) != 0 || (ret = mbedtls_x509_get_alg(&p, end, &crt->sig_oid, &sig_params1)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (ret);
	}

	crt->version++;

	if (crt->version > 3) {
		mbedtls_x509_crt_free(crt);
		return (MBEDTLS_ERR_X509_UNKNOWN_VERSION);
	}

	if ((ret = mbedtls_x509_get_sig_alg(&crt->sig_oid, &sig_params1, &crt->sig_md, &crt->sig_pk, &crt->sig_opts)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (ret);
	}

	/*
	 * issuer               Name
	 */
	crt->issuer_raw.p = p;

	if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (MBEDTLS_ERR_X509_INVALID_FORMAT + ret);
	}

	if ((ret = mbedtls_x509_get_name(&p, p + len, &crt->issuer)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (ret);
	}

	crt->issuer_raw.len = p - crt->issuer_raw.p;

	/*
	 * Validity ::= SEQUENCE {
	 *      notBefore      Time,
	 *      notAfter       Time }
	 *
	 */
	if ((ret = x509_get_dates(&p, end, &crt->valid_from, &crt->valid_to)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (ret);
	}

	/*
	 * subject              Name
	 */
	crt->subject_raw.p = p;

	if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (MBEDTLS_ERR_X509_INVALID_FORMAT + ret);
	}

	if (len && (ret = mbedtls_x509_get_name(&p, p + len, &crt->subject)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (ret);
	}

	crt->subject_raw.len = p - crt->subject_raw.p;

	/*
	 * SubjectPublicKeyInfo
	 */
	if ((ret = mbedtls_pk_parse_subpubkey(&p, end, &crt->pk)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (ret);
	}

	/*
	 *  issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL,
	 *                       -- If present, version shall be v2 or v3
	 *  subjectUniqueID [2]  IMPLICIT UniqueIdentifier OPTIONAL,
	 *                       -- If present, version shall be v2 or v3
	 *  extensions      [3]  EXPLICIT Extensions OPTIONAL
	 *                       -- If present, version shall be v3
	 */
	if (crt->version == 2 || crt->version == 3) {
		ret = x509_get_uid(&p, end, &crt->issuer_id, 1);
		if (ret != 0) {
			mbedtls_x509_crt_free(crt);
			return (ret);
		}
	}

	if (crt->version == 2 || crt->version == 3) {
		ret = x509_get_uid(&p, end, &crt->subject_id, 2);
		if (ret != 0) {
			mbedtls_x509_crt_free(crt);
			return (ret);
		}
	}
#if !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3)
	if (crt->version == 3)
#endif
	{
		ret = x509_get_crt_ext(&p, end, crt);
		if (ret != 0) {
			mbedtls_x509_crt_free(crt);
			return (ret);
		}
	}

	if (p != end) {
		mbedtls_x509_crt_free(crt);
		return (MBEDTLS_ERR_X509_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	end = crt_end;

	/*
	 *  }
	 *  -- end of TBSCertificate
	 *
	 *  signatureAlgorithm   AlgorithmIdentifier,
	 *  signatureValue       BIT STRING
	 */
	if ((ret = mbedtls_x509_get_alg(&p, end, &sig_oid2, &sig_params2)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (ret);
	}

	if (crt->sig_oid.len != sig_oid2.len || memcmp(crt->sig_oid.p, sig_oid2.p, crt->sig_oid.len) != 0 || sig_params1.len != sig_params2.len || (sig_params1.len != 0 && memcmp(sig_params1.p, sig_params2.p, sig_params1.len) != 0)) {
		mbedtls_x509_crt_free(crt);
		return (MBEDTLS_ERR_X509_SIG_MISMATCH);
	}

	if ((ret = mbedtls_x509_get_sig(&p, end, &crt->sig)) != 0) {
		mbedtls_x509_crt_free(crt);
		return (ret);
	}

	if (p != end) {
		mbedtls_x509_crt_free(crt);
		return (MBEDTLS_ERR_X509_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	return (0);
}

/*
 * Parse one X.509 certificate in DER format from a buffer and add them to a
 * chained list
 */
int mbedtls_x509_crt_parse_der(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen)
{
	int ret;
	mbedtls_x509_crt *crt = chain, *prev = NULL;

	/*
	 * Check for valid input
	 */
	if (crt == NULL || buf == NULL) {
		return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
	}

	while (crt->version != 0 && crt->next != NULL) {
		prev = crt;
		crt = crt->next;
	}

	/*
	 * Add new certificate on the end of the chain if needed.
	 */
	if (crt->version != 0 && crt->next == NULL) {
		crt->next = mbedtls_calloc(1, sizeof(mbedtls_x509_crt));

		if (crt->next == NULL) {
			return (MBEDTLS_ERR_X509_ALLOC_FAILED);
		}

		prev = crt;
		mbedtls_x509_crt_init(crt->next);
		crt = crt->next;
	}

	if ((ret = x509_crt_parse_der_core(crt, buf, buflen)) != 0) {
		if (prev) {
			prev->next = NULL;
		}

		if (crt != chain) {
			mbedtls_free(crt);
		}

		return (ret);
	}

	return (0);
}

/*
 * Parse one or more PEM certificates from a buffer and add them to the chained
 * list
 */
int mbedtls_x509_crt_parse(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen)
{
	int success = 0, first_error = 0, total_failed = 0;
#if defined(MBEDTLS_PEM_PARSE_C)
	int buf_format = MBEDTLS_X509_FORMAT_DER;
#endif

	/*
	 * Check for valid input
	 */
	if (chain == NULL || buf == NULL) {
		return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
	}

	/*
	 * Determine buffer content. Buffer contains either one DER certificate or
	 * one or more PEM certificates.
	 */
#if defined(MBEDTLS_PEM_PARSE_C)
	if (buflen != 0 && buf[buflen - 1] == '\0' && strstr((const char *)buf, "-----BEGIN CERTIFICATE-----") != NULL) {
		buf_format = MBEDTLS_X509_FORMAT_PEM;
	}

	if (buf_format == MBEDTLS_X509_FORMAT_DER) {
		return mbedtls_x509_crt_parse_der(chain, buf, buflen);
	}
#else
	return mbedtls_x509_crt_parse_der(chain, buf, buflen);
#endif

#if defined(MBEDTLS_PEM_PARSE_C)
	if (buf_format == MBEDTLS_X509_FORMAT_PEM) {
		int ret;
		mbedtls_pem_context pem;

		/* 1 rather than 0 since the terminating NULL byte is counted in */
		while (buflen > 1) {
			size_t use_len;
			mbedtls_pem_init(&pem);

			/* If we get there, we know the string is null-terminated */
			ret = mbedtls_pem_read_buffer(&pem, "-----BEGIN CERTIFICATE-----", "-----END CERTIFICATE-----", buf, NULL, 0, &use_len);

			if (ret == 0) {
				/*
				 * Was PEM encoded
				 */
				buflen -= use_len;
				buf += use_len;
			} else if (ret == MBEDTLS_ERR_PEM_BAD_INPUT_DATA) {
				return (ret);
			} else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
				mbedtls_pem_free(&pem);

				/*
				 * PEM header and footer were found
				 */
				buflen -= use_len;
				buf += use_len;

				if (first_error == 0) {
					first_error = ret;
				}

				total_failed++;
				continue;
			} else {
				break;
			}

			ret = mbedtls_x509_crt_parse_der(chain, pem.buf, pem.buflen);

			mbedtls_pem_free(&pem);

			if (ret != 0) {
				/*
				 * Quit parsing on a memory error
				 */
				if (ret == MBEDTLS_ERR_X509_ALLOC_FAILED) {
					return (ret);
				}

				if (first_error == 0) {
					first_error = ret;
				}

				total_failed++;
				continue;
			}

			success = 1;
		}
	}

	if (success) {
		return (total_failed);
	} else if (first_error) {
		return (first_error);
	} else {
		return (MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT);
	}
#endif							/* MBEDTLS_PEM_PARSE_C */
}

#if defined(MBEDTLS_FS_IO)
/*
 * Load one or more certificates and add them to the chained list
 */
int mbedtls_x509_crt_parse_file(mbedtls_x509_crt *chain, const char *path)
{
	int ret;
	size_t n;
	unsigned char *buf;

	if ((ret = mbedtls_pk_load_file(path, &buf, &n)) != 0) {
		return (ret);
	}

	ret = mbedtls_x509_crt_parse(chain, buf, n);

	mbedtls_zeroize(buf, n);
	mbedtls_free(buf);

	return (ret);
}

int mbedtls_x509_crt_parse_path(mbedtls_x509_crt *chain, const char *path)
{
	int ret = 0;
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
	int w_ret;
	WCHAR szDir[MAX_PATH];
	char filename[MAX_PATH];
	char *p;
	size_t len = strlen(path);
	int lengthAsInt = 0;

	WIN32_FIND_DATAW file_data;
	HANDLE hFind;

	if (len > MAX_PATH - 3) {
		return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
	}

	memset(szDir, 0, sizeof(szDir));
	memset(filename, 0, MAX_PATH);
	memcpy(filename, path, len);
	filename[len++] = '\\';
	p = filename + len;
	filename[len++] = '*';

	if (FAILED(SizeTToInt(len, &lengthAsInt))) {
		return (MBEDTLS_ERR_X509_FILE_IO_ERROR);
	}

	w_ret = MultiByteToWideChar(CP_ACP, 0, filename, lengthAsInt, szDir, MAX_PATH - 3);
	if (w_ret == 0) {
		return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
	}

	hFind = FindFirstFileW(szDir, &file_data);
	if (hFind == INVALID_HANDLE_VALUE) {
		return (MBEDTLS_ERR_X509_FILE_IO_ERROR);
	}

	len = MAX_PATH - len;
	do {
		memset(p, 0, len);

		if (file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
			continue;
		}

		if (FAILED(SizeTToInt(wcslen(file_data.cFileName), &lengthAsInt))) {
			return (MBEDTLS_ERR_X509_FILE_IO_ERROR);
		}

		w_ret = WideCharToMultiByte(CP_ACP, 0, file_data.cFileName, lengthAsInt, p, (int)len - 1, NULL, NULL);
		if (w_ret == 0) {
			return (MBEDTLS_ERR_X509_FILE_IO_ERROR);
		}

		w_ret = mbedtls_x509_crt_parse_file(chain, filename);
		if (w_ret < 0) {
			ret++;
		} else {
			ret += w_ret;
		}
	} while (FindNextFileW(hFind, &file_data) != 0);

	if (GetLastError() != ERROR_NO_MORE_FILES) {
		ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
	}

	FindClose(hFind);
#else							/* _WIN32 */
	int t_ret;
	int snp_ret;
	struct stat sb;
	struct dirent *entry;
	char entry_name[MBEDTLS_X509_MAX_FILE_PATH_LEN];
	DIR *dir = opendir(path);

	if (dir == NULL) {
		return (MBEDTLS_ERR_X509_FILE_IO_ERROR);
	}
#if defined(MBEDTLS_THREADING_PTHREAD)
	if ((ret = mbedtls_mutex_lock(&mbedtls_threading_readdir_mutex)) != 0) {
		closedir(dir);
		return (ret);
	}
#endif

	while ((entry = readdir(dir)) != NULL) {
		snp_ret = mbedtls_snprintf(entry_name, sizeof entry_name, "%s/%s", path, entry->d_name);

		if (snp_ret < 0 || (size_t)snp_ret >= sizeof entry_name) {
			ret = MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
			goto cleanup;
		} else if (stat(entry_name, &sb) == -1) {
			ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
			goto cleanup;
		}

		if (!S_ISREG(sb.st_mode)) {
			continue;
		}
		// Ignore parse errors
		//
		t_ret = mbedtls_x509_crt_parse_file(chain, entry_name);
		if (t_ret < 0) {
			ret++;
		} else {
			ret += t_ret;
		}
	}

cleanup:
	closedir(dir);

#if defined(MBEDTLS_THREADING_PTHREAD)
	if (mbedtls_mutex_unlock(&mbedtls_threading_readdir_mutex) != 0) {
		ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
	}
#endif

#endif							/* _WIN32 */

	return (ret);
}
#endif							/* MBEDTLS_FS_IO */

static int x509_info_subject_alt_name(char **buf, size_t *size, const mbedtls_x509_sequence *subject_alt_name)
{
	size_t i;
	size_t n = *size;
	char *p = *buf;
	const mbedtls_x509_sequence *cur = subject_alt_name;
	const char *sep = "";
	size_t sep_len = 0;

	while (cur != NULL) {
		if (cur->buf.len + sep_len >= n) {
			*p = '\0';
			return (MBEDTLS_ERR_X509_BUFFER_TOO_SMALL);
		}

		n -= cur->buf.len + sep_len;
		for (i = 0; i < sep_len; i++) {
			*p++ = sep[i];
		}
		for (i = 0; i < cur->buf.len; i++) {
			*p++ = cur->buf.p[i];
		}

		sep = ", ";
		sep_len = 2;

		cur = cur->next;
	}

	*p = '\0';

	*size = n;
	*buf = p;

	return (0);
}

#define PRINT_ITEM(i)                           \
{                                           \
ret = mbedtls_snprintf(p, n, "%s" i, sep);    \
MBEDTLS_X509_SAFE_SNPRINTF;                        \
sep = ", ";                             \
}

#define CERT_TYPE(type, name)                    \
if (ns_cert_type & type)                   \
PRINT_ITEM(name);

static int x509_info_cert_type(char **buf, size_t *size, unsigned char ns_cert_type)
{
	int ret;
	size_t n = *size;
	char *p = *buf;
	const char *sep = "";

	CERT_TYPE(MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT, "SSL Client");
	CERT_TYPE(MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER, "SSL Server");
	CERT_TYPE(MBEDTLS_X509_NS_CERT_TYPE_EMAIL, "Email");
	CERT_TYPE(MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING, "Object Signing");
	CERT_TYPE(MBEDTLS_X509_NS_CERT_TYPE_RESERVED, "Reserved");
	CERT_TYPE(MBEDTLS_X509_NS_CERT_TYPE_SSL_CA, "SSL CA");
	CERT_TYPE(MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA, "Email CA");
	CERT_TYPE(MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA, "Object Signing CA");

	*size = n;
	*buf = p;

	return (0);
}

#define KEY_USAGE(code, name)    \
if (key_usage & code)      \
PRINT_ITEM(name);

static int x509_info_key_usage(char **buf, size_t *size, unsigned int key_usage)
{
	int ret;
	size_t n = *size;
	char *p = *buf;
	const char *sep = "";

	KEY_USAGE(MBEDTLS_X509_KU_DIGITAL_SIGNATURE, "Digital Signature");
	KEY_USAGE(MBEDTLS_X509_KU_NON_REPUDIATION, "Non Repudiation");
	KEY_USAGE(MBEDTLS_X509_KU_KEY_ENCIPHERMENT, "Key Encipherment");
	KEY_USAGE(MBEDTLS_X509_KU_DATA_ENCIPHERMENT, "Data Encipherment");
	KEY_USAGE(MBEDTLS_X509_KU_KEY_AGREEMENT, "Key Agreement");
	KEY_USAGE(MBEDTLS_X509_KU_KEY_CERT_SIGN, "Key Cert Sign");
	KEY_USAGE(MBEDTLS_X509_KU_CRL_SIGN, "CRL Sign");
	KEY_USAGE(MBEDTLS_X509_KU_ENCIPHER_ONLY, "Encipher Only");
	KEY_USAGE(MBEDTLS_X509_KU_DECIPHER_ONLY, "Decipher Only");

	*size = n;
	*buf = p;

	return (0);
}

static int x509_info_ext_key_usage(char **buf, size_t *size, const mbedtls_x509_sequence *extended_key_usage)
{
	int ret;
	const char *desc;
	size_t n = *size;
	char *p = *buf;
	const mbedtls_x509_sequence *cur = extended_key_usage;
	const char *sep = "";

	while (cur != NULL) {
		if (mbedtls_oid_get_extended_key_usage(&cur->buf, &desc) != 0) {
			desc = "???";
		}

		ret = mbedtls_snprintf(p, n, "%s%s", sep, desc);
		MBEDTLS_X509_SAFE_SNPRINTF;

		sep = ", ";

		cur = cur->next;
	}

	*size = n;
	*buf = p;

	return (0);
}

/*
 * Return an informational string about the certificate.
 */
#define BEFORE_COLON    18
#define BC              "18"
int mbedtls_x509_crt_info(char *buf, size_t size, const char *prefix, const mbedtls_x509_crt *crt)
{
	int ret;
	size_t n;
	char *p;
	char key_size_str[BEFORE_COLON];

	p = buf;
	n = size;

	if (NULL == crt) {
		ret = mbedtls_snprintf(p, n, "\nCertificate is uninitialised!\n");
		MBEDTLS_X509_SAFE_SNPRINTF;

		return ((int)(size - n));
	}

	ret = mbedtls_snprintf(p, n, "%scert. version     : %d\n", prefix, crt->version);
	MBEDTLS_X509_SAFE_SNPRINTF;
	ret = mbedtls_snprintf(p, n, "%sserial number     : ", prefix);
	MBEDTLS_X509_SAFE_SNPRINTF;

	ret = mbedtls_x509_serial_gets(p, n, &crt->serial);
	MBEDTLS_X509_SAFE_SNPRINTF;

	ret = mbedtls_snprintf(p, n, "\n%sissuer name       : ", prefix);
	MBEDTLS_X509_SAFE_SNPRINTF;
	ret = mbedtls_x509_dn_gets(p, n, &crt->issuer);
	MBEDTLS_X509_SAFE_SNPRINTF;

	ret = mbedtls_snprintf(p, n, "\n%ssubject name      : ", prefix);
	MBEDTLS_X509_SAFE_SNPRINTF;
	ret = mbedtls_x509_dn_gets(p, n, &crt->subject);
	MBEDTLS_X509_SAFE_SNPRINTF;

	ret = mbedtls_snprintf(p, n, "\n%sissued  on        : " "%04d-%02d-%02d %02d:%02d:%02d", prefix, crt->valid_from.year, crt->valid_from.mon, crt->valid_from.day, crt->valid_from.hour, crt->valid_from.min, crt->valid_from.sec);
	MBEDTLS_X509_SAFE_SNPRINTF;

	ret = mbedtls_snprintf(p, n, "\n%sexpires on        : " "%04d-%02d-%02d %02d:%02d:%02d", prefix, crt->valid_to.year, crt->valid_to.mon, crt->valid_to.day, crt->valid_to.hour, crt->valid_to.min, crt->valid_to.sec);
	MBEDTLS_X509_SAFE_SNPRINTF;

	ret = mbedtls_snprintf(p, n, "\n%ssigned using      : ", prefix);
	MBEDTLS_X509_SAFE_SNPRINTF;

	ret = mbedtls_x509_sig_alg_gets(p, n, &crt->sig_oid, crt->sig_pk, crt->sig_md, crt->sig_opts);
	MBEDTLS_X509_SAFE_SNPRINTF;

	/* Key size */
	if ((ret = mbedtls_x509_key_size_helper(key_size_str, BEFORE_COLON, mbedtls_pk_get_name(&crt->pk))) != 0) {
		return (ret);
	}

	ret = mbedtls_snprintf(p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str, (int)mbedtls_pk_get_bitlen(&crt->pk));
	MBEDTLS_X509_SAFE_SNPRINTF;

	/*
	 * Optional extensions
	 */

	if (crt->ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS) {
		ret = mbedtls_snprintf(p, n, "\n%sbasic constraints : CA=%s", prefix, crt->ca_istrue ? "true" : "false");
		MBEDTLS_X509_SAFE_SNPRINTF;

		if (crt->max_pathlen > 0) {
			ret = mbedtls_snprintf(p, n, ", max_pathlen=%d", crt->max_pathlen - 1);
			MBEDTLS_X509_SAFE_SNPRINTF;
		}
	}

	if (crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME) {
		ret = mbedtls_snprintf(p, n, "\n%ssubject alt name  : ", prefix);
		MBEDTLS_X509_SAFE_SNPRINTF;

		if ((ret = x509_info_subject_alt_name(&p, &n, &crt->subject_alt_names)) != 0) {
			return (ret);
		}
	}

	if (crt->ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE) {
		ret = mbedtls_snprintf(p, n, "\n%scert. type        : ", prefix);
		MBEDTLS_X509_SAFE_SNPRINTF;

		if ((ret = x509_info_cert_type(&p, &n, crt->ns_cert_type)) != 0) {
			return (ret);
		}
	}

	if (crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE) {
		ret = mbedtls_snprintf(p, n, "\n%skey usage         : ", prefix);
		MBEDTLS_X509_SAFE_SNPRINTF;

		if ((ret = x509_info_key_usage(&p, &n, crt->key_usage)) != 0) {
			return (ret);
		}
	}

	if (crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE) {
		ret = mbedtls_snprintf(p, n, "\n%sext key usage     : ", prefix);
		MBEDTLS_X509_SAFE_SNPRINTF;

		if ((ret = x509_info_ext_key_usage(&p, &n, &crt->ext_key_usage)) != 0) {
			return (ret);
		}
	}

	ret = mbedtls_snprintf(p, n, "\n");
	MBEDTLS_X509_SAFE_SNPRINTF;

	return ((int)(size - n));
}

struct x509_crt_verify_string {
	int code;
	const char *string;
};

static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
	{MBEDTLS_X509_BADCERT_EXPIRED, "The certificate validity has expired"},
	{MBEDTLS_X509_BADCERT_REVOKED, "The certificate has been revoked (is on a CRL)"},
	{MBEDTLS_X509_BADCERT_CN_MISMATCH, "The certificate Common Name (CN) does not match with the expected CN"},
	{MBEDTLS_X509_BADCERT_NOT_TRUSTED, "The certificate is not correctly signed by the trusted CA"},
	{MBEDTLS_X509_BADCRL_NOT_TRUSTED, "The CRL is not correctly signed by the trusted CA"},
	{MBEDTLS_X509_BADCRL_EXPIRED, "The CRL is expired"},
	{MBEDTLS_X509_BADCERT_MISSING, "Certificate was missing"},
	{MBEDTLS_X509_BADCERT_SKIP_VERIFY, "Certificate verification was skipped"},
	{MBEDTLS_X509_BADCERT_OTHER, "Other reason (can be used by verify callback)"},
	{MBEDTLS_X509_BADCERT_FUTURE, "The certificate validity starts in the future"},
	{MBEDTLS_X509_BADCRL_FUTURE, "The CRL is from the future"},
	{MBEDTLS_X509_BADCERT_KEY_USAGE, "Usage does not match the keyUsage extension"},
	{MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension"},
	{MBEDTLS_X509_BADCERT_NS_CERT_TYPE, "Usage does not match the nsCertType extension"},
	{MBEDTLS_X509_BADCERT_BAD_MD, "The certificate is signed with an unacceptable hash."},
	{MBEDTLS_X509_BADCERT_BAD_PK, "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA)."},
	{MBEDTLS_X509_BADCERT_BAD_KEY, "The certificate is signed with an unacceptable key (eg bad curve, RSA too short)."},
	{MBEDTLS_X509_BADCRL_BAD_MD, "The CRL is signed with an unacceptable hash."},
	{MBEDTLS_X509_BADCRL_BAD_PK, "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA)."},
	{MBEDTLS_X509_BADCRL_BAD_KEY, "The CRL is signed with an unacceptable key (eg bad curve, RSA too short)."},
	{0, NULL}
};

int mbedtls_x509_crt_verify_info(char *buf, size_t size, const char *prefix, uint32_t flags)
{
	int ret;
	const struct x509_crt_verify_string *cur;
	char *p = buf;
	size_t n = size;

	for (cur = x509_crt_verify_strings; cur->string != NULL; cur++) {
		if ((flags & cur->code) == 0) {
			continue;
		}

		ret = mbedtls_snprintf(p, n, "%s%s\n", prefix, cur->string);
		MBEDTLS_X509_SAFE_SNPRINTF;
		flags ^= cur->code;
	}

	if (flags != 0) {
		ret = mbedtls_snprintf(p, n, "%sUnknown reason " "(this should not happen)\n", prefix);
		MBEDTLS_X509_SAFE_SNPRINTF;
	}

	return ((int)(size - n));
}

#if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
int mbedtls_x509_crt_check_key_usage(const mbedtls_x509_crt *crt, unsigned int usage)
{
	unsigned int usage_must, usage_may;
	unsigned int may_mask = MBEDTLS_X509_KU_ENCIPHER_ONLY | MBEDTLS_X509_KU_DECIPHER_ONLY;

	if ((crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE) == 0) {
		return (0);
	}

	usage_must = usage & ~may_mask;

	if (((crt->key_usage & ~may_mask) & usage_must) != usage_must) {
		return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
	}

	usage_may = usage & may_mask;

	if (((crt->key_usage & may_mask) | usage_may) != usage_may) {
		return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
	}

	return (0);
}
#endif

#if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
int mbedtls_x509_crt_check_extended_key_usage(const mbedtls_x509_crt *crt, const char *usage_oid, size_t usage_len)
{
	const mbedtls_x509_sequence *cur;

	/* Extension is not mandatory, absent means no restriction */
	if ((crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE) == 0) {
		return (0);
	}

	/*
	 * Look for the requested usage (or wildcard ANY) in our list
	 */
	for (cur = &crt->ext_key_usage; cur != NULL; cur = cur->next) {
		const mbedtls_x509_buf *cur_oid = &cur->buf;

		if (cur_oid->len == usage_len && memcmp(cur_oid->p, usage_oid, usage_len) == 0) {
			return (0);
		}

		if (MBEDTLS_OID_CMP(MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, cur_oid) == 0) {
			return (0);
		}
	}

	return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
}
#endif							/* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */

#if defined(MBEDTLS_X509_CRL_PARSE_C)
/*
 * Return 1 if the certificate is revoked, or 0 otherwise.
 */
int mbedtls_x509_crt_is_revoked(const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl)
{
	const mbedtls_x509_crl_entry *cur = &crl->entry;

	while (cur != NULL && cur->serial.len != 0) {
		if (crt->serial.len == cur->serial.len && memcmp(crt->serial.p, cur->serial.p, crt->serial.len) == 0) {
			if (mbedtls_x509_time_is_past(&cur->revocation_date)) {
				return (1);
			}
		}

		cur = cur->next;
	}

	return (0);
}

/*
 * Check that the given certificate is not revoked according to the CRL.
 * Skip validation is no CRL for the given CA is present.
 */
static int x509_crt_verifycrl(mbedtls_x509_crt *crt, mbedtls_x509_crt *ca, mbedtls_x509_crl *crl_list, const mbedtls_x509_crt_profile *profile)
{
	int flags = 0;
	unsigned char hash[MBEDTLS_MD_MAX_SIZE];
	const mbedtls_md_info_t *md_info;

	if (ca == NULL) {
		return (flags);
	}

	while (crl_list != NULL) {
		if (crl_list->version == 0 || crl_list->issuer_raw.len != ca->subject_raw.len || memcmp(crl_list->issuer_raw.p, ca->subject_raw.p, crl_list->issuer_raw.len) != 0) {
			crl_list = crl_list->next;
			continue;
		}

		/*
		 * Check if the CA is configured to sign CRLs
		 */
#if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
		if (mbedtls_x509_crt_check_key_usage(ca, MBEDTLS_X509_KU_CRL_SIGN) != 0) {
			flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
			break;
		}
#endif

		/*
		 * Check if CRL is correctly signed by the trusted CA
		 */
		if (x509_profile_check_md_alg(profile, crl_list->sig_md) != 0) {
			flags |= MBEDTLS_X509_BADCRL_BAD_MD;
		}

		if (x509_profile_check_pk_alg(profile, crl_list->sig_pk) != 0) {
			flags |= MBEDTLS_X509_BADCRL_BAD_PK;
		}

		md_info = mbedtls_md_info_from_type(crl_list->sig_md);
		if (md_info == NULL) {
			/*
			 * Cannot check 'unknown' hash
			 */
			flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
			break;
		}

		mbedtls_md(md_info, crl_list->tbs.p, crl_list->tbs.len, hash);

		if (x509_profile_check_key(profile, crl_list->sig_pk, &ca->pk) != 0) {
			flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
		}

		if (mbedtls_pk_verify_ext(crl_list->sig_pk, crl_list->sig_opts, &ca->pk, crl_list->sig_md, hash, mbedtls_md_get_size(md_info), crl_list->sig.p, crl_list->sig.len) != 0) {
			flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
			break;
		}

		/*
		 * Check for validity of CRL (Do not drop out)
		 */
		if (mbedtls_x509_time_is_past(&crl_list->next_update)) {
			flags |= MBEDTLS_X509_BADCRL_EXPIRED;
		}

		if (mbedtls_x509_time_is_future(&crl_list->this_update)) {
			flags |= MBEDTLS_X509_BADCRL_FUTURE;
		}

		/*
		 * Check if certificate is revoked
		 */
		if (mbedtls_x509_crt_is_revoked(crt, crl_list)) {
			flags |= MBEDTLS_X509_BADCERT_REVOKED;
			break;
		}

		crl_list = crl_list->next;
	}

	return (flags);
}
#endif							/* MBEDTLS_X509_CRL_PARSE_C */

/*
 * Like memcmp, but case-insensitive and always returns -1 if different
 */
static int x509_memcasecmp(const void *s1, const void *s2, size_t len)
{
	size_t i;
	unsigned char diff;
	const unsigned char *n1 = s1, *n2 = s2;

	for (i = 0; i < len; i++) {
		diff = n1[i] ^ n2[i];

		if (diff == 0) {
			continue;
		}

		if (diff == 32 && ((n1[i] >= 'a' && n1[i] <= 'z') || (n1[i] >= 'A' && n1[i] <= 'Z'))) {
			continue;
		}

		return (-1);
	}

	return (0);
}

/*
 * Return 0 if name matches wildcard, -1 otherwise
 */
static int x509_check_wildcard(const char *cn, mbedtls_x509_buf *name)
{
	size_t i;
	size_t cn_idx = 0, cn_len = strlen(cn);

	if (name->len < 3 || name->p[0] != '*' || name->p[1] != '.') {
		return (0);
	}

	for (i = 0; i < cn_len; ++i) {
		if (cn[i] == '.') {
			cn_idx = i;
			break;
		}
	}

	if (cn_idx == 0) {
		return (-1);
	}

	if (cn_len - cn_idx == name->len - 1 && x509_memcasecmp(name->p + 1, cn + cn_idx, name->len - 1) == 0) {
		return (0);
	}

	return (-1);
}

/*
 * Compare two X.509 strings, case-insensitive, and allowing for some encoding
 * variations (but not all).
 *
 * Return 0 if equal, -1 otherwise.
 */
static int x509_string_cmp(const mbedtls_x509_buf *a, const mbedtls_x509_buf *b)
{
	if (a->tag == b->tag && a->len == b->len && memcmp(a->p, b->p, b->len) == 0) {
		return (0);
	}

	if ((a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING) && (b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING) && a->len == b->len && x509_memcasecmp(a->p, b->p, b->len) == 0) {
		return (0);
	}

	return (-1);
}

/*
 * Compare two X.509 Names (aka rdnSequence).
 *
 * See RFC 5280 section 7.1, though we don't implement the whole algorithm:
 * we sometimes return unequal when the full algorithm would return equal,
 * but never the other way. (In particular, we don't do Unicode normalisation
 * or space folding.)
 *
 * Return 0 if equal, -1 otherwise.
 */
static int x509_name_cmp(const mbedtls_x509_name *a, const mbedtls_x509_name *b)
{
	/* Avoid recursion, it might not be optimised by the compiler */
	while (a != NULL || b != NULL) {
		if (a == NULL || b == NULL) {
			return (-1);
		}

		/* type */
		if (a->oid.tag != b->oid.tag || a->oid.len != b->oid.len || memcmp(a->oid.p, b->oid.p, b->oid.len) != 0) {
			return (-1);
		}

		/* value */
		if (x509_string_cmp(&a->val, &b->val) != 0) {
			return (-1);
		}

		/* structure of the list of sets */
		if (a->next_merged != b->next_merged) {
			return (-1);
		}

		a = a->next;
		b = b->next;
	}

	/* a == NULL == b */
	return (0);
}

/*
 * Check if 'parent' is a suitable parent (signing CA) for 'child'.
 * Return 0 if yes, -1 if not.
 *
 * top means parent is a locally-trusted certificate
 * bottom means child is the end entity cert
 */
static int x509_crt_check_parent(const mbedtls_x509_crt *child, const mbedtls_x509_crt *parent, int top, int bottom)
{
	int need_ca_bit;

	/* Parent must be the issuer */
	if (x509_name_cmp(&child->issuer, &parent->subject) != 0) {
		return (-1);
	}

	/* Parent must have the basicConstraints CA bit set as a general rule */
	need_ca_bit = 1;

	/* Exception: v1/v2 certificates that are locally trusted. */
	if (top && parent->version < 3) {
		need_ca_bit = 0;
	}

	/* Exception: self-signed end-entity certs that are locally trusted. */
	if (top && bottom && child->raw.len == parent->raw.len && memcmp(child->raw.p, parent->raw.p, child->raw.len) == 0) {
		need_ca_bit = 0;
	}

	if (need_ca_bit && !parent->ca_istrue) {
		return (-1);
	}
#if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
	if (need_ca_bit && mbedtls_x509_crt_check_key_usage(parent, MBEDTLS_X509_KU_KEY_CERT_SIGN) != 0) {
		return (-1);
	}
#endif

	return (0);
}

static int x509_crt_verify_top(mbedtls_x509_crt *child, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const mbedtls_x509_crt_profile *profile, int path_cnt, int self_cnt, uint32_t *flags, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy)
{
	int ret;
	uint32_t ca_flags = 0;
	int check_path_cnt;
	unsigned char hash[MBEDTLS_MD_MAX_SIZE];
	const mbedtls_md_info_t *md_info;

	if (mbedtls_x509_time_is_past(&child->valid_to)) {
		*flags |= MBEDTLS_X509_BADCERT_EXPIRED;
	}

	if (mbedtls_x509_time_is_future(&child->valid_from)) {
		*flags |= MBEDTLS_X509_BADCERT_FUTURE;
	}

	if (x509_profile_check_md_alg(profile, child->sig_md) != 0) {
		*flags |= MBEDTLS_X509_BADCERT_BAD_MD;
	}

	if (x509_profile_check_pk_alg(profile, child->sig_pk) != 0) {
		*flags |= MBEDTLS_X509_BADCERT_BAD_PK;
	}

	/*
	 * Child is the top of the chain. Check against the trust_ca list.
	 */
	*flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;

	md_info = mbedtls_md_info_from_type(child->sig_md);
	if (md_info == NULL) {
		/*
		 * Cannot check 'unknown', no need to try any CA
		 */
		trust_ca = NULL;
	} else {
		mbedtls_md(md_info, child->tbs.p, child->tbs.len, hash);
	}

	for (/* trust_ca */ ; trust_ca != NULL; trust_ca = trust_ca->next) {
		if (x509_crt_check_parent(child, trust_ca, 1, path_cnt == 0) != 0) {
			continue;
		}

		check_path_cnt = path_cnt + 1;

		/*
		 * Reduce check_path_cnt to check against if top of the chain is
		 * the same as the trusted CA
		 */
		if (child->subject_raw.len == trust_ca->subject_raw.len && memcmp(child->subject_raw.p, trust_ca->subject_raw.p, child->issuer_raw.len) == 0) {
			check_path_cnt--;
		}

		/* Self signed certificates do not count towards the limit */
		if (trust_ca->max_pathlen > 0 && trust_ca->max_pathlen < check_path_cnt - self_cnt) {
			continue;
		}

		if (mbedtls_x509_time_is_past(&trust_ca->valid_to)) {
			continue;
		}

		if (mbedtls_x509_time_is_future(&trust_ca->valid_from)) {
			continue;
		}

		if (mbedtls_pk_verify_ext(child->sig_pk, child->sig_opts, &trust_ca->pk, child->sig_md, hash, mbedtls_md_get_size(md_info), child->sig.p, child->sig.len) != 0) {
			continue;
		}

		/*
		 * Top of chain is signed by a trusted CA
		 */
		*flags &= ~MBEDTLS_X509_BADCERT_NOT_TRUSTED;

		if (x509_profile_check_key(profile, child->sig_pk, &trust_ca->pk) != 0) {
			*flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
		}

		break;
	}

	/*
	 * If top of chain is not the same as the trusted CA send a verify request
	 * to the callback for any issues with validity and CRL presence for the
	 * trusted CA certificate.
	 */
	if (trust_ca != NULL && (child->subject_raw.len != trust_ca->subject_raw.len || memcmp(child->subject_raw.p, trust_ca->subject_raw.p, child->issuer_raw.len) != 0)) {
#if defined(MBEDTLS_X509_CRL_PARSE_C)
		/* Check trusted CA's CRL for the chain's top crt */
		*flags |= x509_crt_verifycrl(child, trust_ca, ca_crl, profile);
#else
		((void)ca_crl);
#endif

		if (NULL != f_vrfy) {
			if ((ret = f_vrfy(p_vrfy, trust_ca, path_cnt + 1, &ca_flags)) != 0) {
				return (ret);
			}
		}
	}

	/* Call callback on top cert */
	if (NULL != f_vrfy) {
		if ((ret = f_vrfy(p_vrfy, child, path_cnt, flags)) != 0) {
			return (ret);
		}
	}

	*flags |= ca_flags;

	return (0);
}

static int x509_crt_verify_child(mbedtls_x509_crt *child, mbedtls_x509_crt *parent, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const mbedtls_x509_crt_profile *profile, int path_cnt, int self_cnt, uint32_t *flags, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy)
{
	int ret;
	uint32_t parent_flags = 0;
	unsigned char hash[MBEDTLS_MD_MAX_SIZE];
	mbedtls_x509_crt *grandparent;
	const mbedtls_md_info_t *md_info;

	/* Counting intermediate self signed certificates */
	if ((path_cnt != 0) && x509_name_cmp(&child->issuer, &child->subject) == 0) {
		self_cnt++;
	}

	/* path_cnt is 0 for the first intermediate CA */
	if (1 + path_cnt > MBEDTLS_X509_MAX_INTERMEDIATE_CA) {
		*flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
		return (MBEDTLS_ERR_X509_CERT_VERIFY_FAILED);
	}

	if (mbedtls_x509_time_is_past(&child->valid_to)) {
		*flags |= MBEDTLS_X509_BADCERT_EXPIRED;
	}

	if (mbedtls_x509_time_is_future(&child->valid_from)) {
		*flags |= MBEDTLS_X509_BADCERT_FUTURE;
	}

	if (x509_profile_check_md_alg(profile, child->sig_md) != 0) {
		*flags |= MBEDTLS_X509_BADCERT_BAD_MD;
	}

	if (x509_profile_check_pk_alg(profile, child->sig_pk) != 0) {
		*flags |= MBEDTLS_X509_BADCERT_BAD_PK;
	}

	md_info = mbedtls_md_info_from_type(child->sig_md);
	if (md_info == NULL) {
		/*
		 * Cannot check 'unknown' hash
		 */
		*flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
	} else {
		mbedtls_md(md_info, child->tbs.p, child->tbs.len, hash);

		if (x509_profile_check_key(profile, child->sig_pk, &parent->pk) != 0) {
			*flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
		}

		if (mbedtls_pk_verify_ext(child->sig_pk, child->sig_opts, &parent->pk, child->sig_md, hash, mbedtls_md_get_size(md_info), child->sig.p, child->sig.len) != 0) {
			*flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
		}
	}

#if defined(MBEDTLS_X509_CRL_PARSE_C)
	/* Check trusted CA's CRL for the given crt */
	*flags |= x509_crt_verifycrl(child, parent, ca_crl, profile);
#endif

	/* Look for a grandparent in trusted CAs */
	for (grandparent = trust_ca; grandparent != NULL; grandparent = grandparent->next) {
		if (x509_crt_check_parent(parent, grandparent, 0, path_cnt == 0) == 0) {
			break;
		}
	}

	if (grandparent != NULL) {
		ret = x509_crt_verify_top(parent, grandparent, ca_crl, profile, path_cnt + 1, self_cnt, &parent_flags, f_vrfy, p_vrfy);
		if (ret != 0) {
			return (ret);
		}
	} else {
		/* Look for a grandparent upwards the chain */
		for (grandparent = parent->next; grandparent != NULL; grandparent = grandparent->next) {
			/* +2 because the current step is not yet accounted for
			 * and because max_pathlen is one higher than it should be.
			 * Also self signed certificates do not count to the limit. */
			if (grandparent->max_pathlen > 0 && grandparent->max_pathlen < 2 + path_cnt - self_cnt) {
				continue;
			}

			if (x509_crt_check_parent(parent, grandparent, 0, path_cnt == 0) == 0) {
				break;
			}
		}

		/* Is our parent part of the chain or at the top? */
		if (grandparent != NULL) {
			ret = x509_crt_verify_child(parent, grandparent, trust_ca, ca_crl, profile, path_cnt + 1, self_cnt, &parent_flags, f_vrfy, p_vrfy);
			if (ret != 0) {
				return (ret);
			}
		} else {
			ret = x509_crt_verify_top(parent, trust_ca, ca_crl, profile, path_cnt + 1, self_cnt, &parent_flags, f_vrfy, p_vrfy);
			if (ret != 0) {
				return (ret);
			}
		}
	}

	/* child is verified to be a child of the parent, call verify callback */
	if (NULL != f_vrfy)
		if ((ret = f_vrfy(p_vrfy, child, path_cnt, flags)) != 0) {
			return (ret);
		}

	*flags |= parent_flags;

	return (0);
}

/*
 * Verify the certificate validity
 */
int mbedtls_x509_crt_verify(mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const char *cn, uint32_t *flags, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy)
{
	return (mbedtls_x509_crt_verify_with_profile(crt, trust_ca, ca_crl, &mbedtls_x509_crt_profile_default, cn, flags, f_vrfy, p_vrfy));
}

/*
 * Verify the certificate validity, with profile
 */
int mbedtls_x509_crt_verify_with_profile(mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const mbedtls_x509_crt_profile *profile, const char *cn, uint32_t *flags, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy)
{
	size_t cn_len;
	int ret;
	int pathlen = 0, selfsigned = 0;
	mbedtls_x509_crt *parent;
	mbedtls_x509_name *name;
	mbedtls_x509_sequence *cur = NULL;
	mbedtls_pk_type_t pk_type;

	if (profile == NULL) {
		return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
	}

	*flags = 0;

	if (cn != NULL) {
		name = &crt->subject;
		cn_len = strlen(cn);

		if (crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME) {
			cur = &crt->subject_alt_names;

			while (cur != NULL) {
				if (cur->buf.len == cn_len && x509_memcasecmp(cn, cur->buf.p, cn_len) == 0) {
					break;
				}

				if (cur->buf.len > 2 && memcmp(cur->buf.p, "*.", 2) == 0 && x509_check_wildcard(cn, &cur->buf) == 0) {
					break;
				}

				cur = cur->next;
			}

			if (cur == NULL) {
				*flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
			}
		} else {
			while (name != NULL) {
				if (MBEDTLS_OID_CMP(MBEDTLS_OID_AT_CN, &name->oid) == 0) {
					if (name->val.len == cn_len && x509_memcasecmp(name->val.p, cn, cn_len) == 0) {
						break;
					}

					if (name->val.len > 2 && memcmp(name->val.p, "*.", 2) == 0 && x509_check_wildcard(cn, &name->val) == 0) {
						break;
					}
				}

				name = name->next;
			}

			if (name == NULL) {
				*flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
			}
		}
	}

	/* Check the type and size of the key */
	pk_type = mbedtls_pk_get_type(&crt->pk);

	if (x509_profile_check_pk_alg(profile, pk_type) != 0) {
		*flags |= MBEDTLS_X509_BADCERT_BAD_PK;
	}

	if (x509_profile_check_key(profile, pk_type, &crt->pk) != 0) {
		*flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
	}

	/* Look for a parent in trusted CAs */
	for (parent = trust_ca; parent != NULL; parent = parent->next) {
		if (x509_crt_check_parent(crt, parent, 0, pathlen == 0) == 0) {
			break;
		}
	}

	if (parent != NULL) {
		ret = x509_crt_verify_top(crt, parent, ca_crl, profile, pathlen, selfsigned, flags, f_vrfy, p_vrfy);
		if (ret != 0) {
			return (ret);
		}
	} else {
		/* Look for a parent upwards the chain */
		for (parent = crt->next; parent != NULL; parent = parent->next)
			if (x509_crt_check_parent(crt, parent, 0, pathlen == 0) == 0) {
				break;
			}

		/* Are we part of the chain or at the top? */
		if (parent != NULL) {
			ret = x509_crt_verify_child(crt, parent, trust_ca, ca_crl, profile, pathlen, selfsigned, flags, f_vrfy, p_vrfy);
			if (ret != 0) {
				return (ret);
			}
		} else {
			ret = x509_crt_verify_top(crt, trust_ca, ca_crl, profile, pathlen, selfsigned, flags, f_vrfy, p_vrfy);
			if (ret != 0) {
				return (ret);
			}
		}
	}

	if (*flags != 0) {
		return (MBEDTLS_ERR_X509_CERT_VERIFY_FAILED);
	}

	return (0);
}

/*
 * Initialize a certificate chain
 */
void mbedtls_x509_crt_init(mbedtls_x509_crt *crt)
{
	memset(crt, 0, sizeof(mbedtls_x509_crt));
}

/*
 * Unallocate all certificate data
 */
void mbedtls_x509_crt_free(mbedtls_x509_crt *crt)
{
	mbedtls_x509_crt *cert_cur = crt;
	mbedtls_x509_crt *cert_prv;
	mbedtls_x509_name *name_cur;
	mbedtls_x509_name *name_prv;
	mbedtls_x509_sequence *seq_cur;
	mbedtls_x509_sequence *seq_prv;

	if (crt == NULL) {
		return;
	}

	do {
		mbedtls_pk_free(&cert_cur->pk);

#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
		mbedtls_free(cert_cur->sig_opts);
#endif

		name_cur = cert_cur->issuer.next;
		while (name_cur != NULL) {
			name_prv = name_cur;
			name_cur = name_cur->next;
			mbedtls_zeroize(name_prv, sizeof(mbedtls_x509_name));
			mbedtls_free(name_prv);
		}

		name_cur = cert_cur->subject.next;
		while (name_cur != NULL) {
			name_prv = name_cur;
			name_cur = name_cur->next;
			mbedtls_zeroize(name_prv, sizeof(mbedtls_x509_name));
			mbedtls_free(name_prv);
		}

		seq_cur = cert_cur->ext_key_usage.next;
		while (seq_cur != NULL) {
			seq_prv = seq_cur;
			seq_cur = seq_cur->next;
			mbedtls_zeroize(seq_prv, sizeof(mbedtls_x509_sequence));
			mbedtls_free(seq_prv);
		}

		seq_cur = cert_cur->subject_alt_names.next;
		while (seq_cur != NULL) {
			seq_prv = seq_cur;
			seq_cur = seq_cur->next;
			mbedtls_zeroize(seq_prv, sizeof(mbedtls_x509_sequence));
			mbedtls_free(seq_prv);
		}

		if (cert_cur->raw.p != NULL) {
			mbedtls_zeroize(cert_cur->raw.p, cert_cur->raw.len);
			mbedtls_free(cert_cur->raw.p);
		}

		cert_cur = cert_cur->next;
	} while (cert_cur != NULL);

	cert_cur = crt;
	do {
		cert_prv = cert_cur;
		cert_cur = cert_cur->next;

		mbedtls_zeroize(cert_prv, sizeof(mbedtls_x509_crt));
		if (cert_prv != crt) {
			mbedtls_free(cert_prv);
		}
	} while (cert_cur != NULL);
}

#endif							/* MBEDTLS_X509_CRT_PARSE_C */
